Engine/Transmission (1998.5 - 2002) Re-tapping oil filter housing threads

[MacGreenie]

I have a Westach combination temp/pressure sensor in the top of the oil pressure housing and it is leaking (weeping) fairly significantly.



It is a 1/8 NPT threaded fitting. Possibly it was tightened too much and no amount of thread sealer seems to work so I think I need to remove the darn thing and fix the threads on the workbench.



Can this thread repair be done on the vehicle? I worry about metal shavings going into the oil stream, however, so this on -vehicle repair may not be the way to go. I would like to do the repair the easiest way possible.



If I do remove the oil filter housing and oil cooler that lives underneath it, is there anything I should look out for? it seems to be a straightforward removal of about a dozen bolts and the replacement of two large gaskets beneath.



Anything under there that takes any special talent?



Any advice on repairing the threads?



They are not cross-threaded. It just seems the steel threads in the aluminum housing caused saome "fretting" and now leakage results when under oil pressure.



Thanks everyone... . I need to get back on the road!



MacGreenie

 

[y-knot]

The housing is aluminum and probably cracked. Pipe threads have a taper to them and with aluminum that is usually what happens when over tightened. I monitor my oil pressure and temperature from that same spot, you just have to be very careful when tightening a fitting there.

I f it was me, I would remove the piece, and maybe try drilling it out and tapping it to 1/4,or 3/8. it would depend on the size and type of crack. You have nothing to lose,if it doesn't work you will still have to get a new one, so why not? I buy all my welding supplies from BOC Gases, they have a product that has two parts mixed together, like an epoxy. But this stuff is made to repair aluminum. I fooled around with it at a open house they had, it is remarkable. Once it has hardened, it can be machined or taped. If they have it around you, you could probably clean the part super good, and fill the 1/8 hole with it, then drill back out and tap? Sorry I don't recall the name of the product. It wasn't J B Weld, something else. Good luck.

 

[MacGreenie]

Thanks... I will investigate this.



You are right. Probably cracked it. I consider it a self-inflicted gunshot wound! Good thing I have nor shot all my toes off!



I will most likely go to my friendly Cummins Dealer and get a new part and gaskets just to ensure a quality fix.



Thanks for chiming in... I will let you know how it goes.

 

[jwilliams3]

What I think you have done is just stripped the threads out or oversized the descending diameter.



I would suggest removing the filter housing, inspect.

Once you have it off you could probably go oversize and re-tap, then use a conversion to run your sender.



Or just buy a new unit.



Anyhow, good luck!



--Justin

 

[Gary - K7GLD]

Don't overlook JB Weld as a possibility - it works in more applications than most epoxies, even in reasonably hot and oily ones - whichever you select, clean the affected area VERY carefully to get a good bond.



Good luck.

 

[britannic]

Presuming the fitting is brass (obviously steel is out of the question ), did you try PTFE tape? Too much can also cause cracks, but for most applications where the temperature range isn't to drastic, it works well.



THe other possibility, which you've probably already checked, is that the sender itself is leaking.